Systems and methods for controlling operations of a heating and cooling system

• US 10,247,436 B2
• Filed: 09/07/2016
• Issued: 04/02/2019
• Est. Priority Date: 09/07/2016
• Status: Active Grant

• Current Assignee: SolarCity Corporation (Tesla Inc.)
• Original Assignee: SolarCity Corporation (Tesla Inc.)
• Inventors: Carlson, Eric Daniel, Zimmerly, Brian L.
• Primary Examiner(s): Bahta, Kidest
• Application Number:
  US15/258,905
• Publication Number:
  US 20180066860A1
• Time in Patent Office: 937 Days
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/65 for selecting an operating mode
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2130/00 Control inputs relating to environmental factors not covered by group F24F2110/00
• CPC Class Codes: F24F 2130/10 Weather information or forecasts
• CPC Class Codes: F24F 2140/50 Load
• CPC Class Codes: F24F 2140/60 Energy consumption
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 2219/2642 Domotique, domestic, home control, automation, smart house
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

Techniques for controlling a heating, ventilation and air conditioning (HVAC) system at a site are disclosed. A disclosed method includes obtaining or calculating a net load at the site and obtaining a temperature of the site during a time period. The method further includes comparing the net load to a threshold load value and comparing the temperature to a lower threshold temperature or an upper threshold temperature. The method also includes determining one or more operation parameter values for the HVAC system based at least in part on the comparison of the net load to the threshold load value and the comparison of the temperature to the lower threshold temperature or the upper threshold temperature, and setting the HVAC system based on the one or more operation parameter values.

Claims

1. A method of controlling a heating, ventilation and air conditioning (HVAC) system at a site having an energy generation (EG) system, the method comprising:

obtaining one or more operation parameter values for the HVAC system;

obtaining a net load at the site during a time period, the net load indicating a difference between a gross electric load at the site and an output of the EG system at the site, wherein the EG system includes a photovoltaic system;

obtaining a temperature of the site during the time period;

comparing, with a processor, the net load to a threshold load value;

comparing, with the processor, the temperature to at least one of a lower threshold temperature or an upper threshold temperature of the one or more operation parameter values;

determining one or more new operation parameter values for the HVAC system based, at least in part, on the comparison of the net load to the threshold load value and the comparison of the temperature to the lower threshold temperature or the upper threshold temperature; and

controlling the HVAC system based on the determined one or more new operation parameter values.

2. The method of claim 1, wherein determining the one or more new operation parameter values for the HVAC system includes:

when the net load is below the threshold load value, determining the one or more new operation parameter values for the HVAC system to increase a power consumption of the HVAC system;

or

when the net load is at or above the threshold load value, determining the one or more new operation parameter values for the HVAC system based on at least one of a predicted future net load or information regarding a current energy price and a future energy price.

3. The method of claim 2, wherein increasing the power consumption of the HVAC system includes at least one of:

setting the HVAC system to a high power mode;

setting the HVAC system to a low power mode;

decreasing a temperature set point of the HVAC system;

or

increasing a speed of a fan of the HVAC system.

4. The method of claim 2, wherein increasing the power consumption of the HVAC system includes:

determining whether a high power mode of the HVAC system can be supported while keeping the net load below the threshold load value; and

performing one of

setting the HVAC system to the high power mode when the high power mode of the HVAC system can be supported while keeping the net load below the threshold load value; and

setting the HVAC system to a low power mode when the high power mode of the HVAC system cannot be supported while keeping the net load below the threshold load value.

5. The method of claim 2, further comprising:

predicting a future gross electric load and a future output of the EG system based on at least one of historical data or weather forecast; and

determining the predicted future net load based on the predicted future gross electric load and the predicted future output of the EG system.

6. The method of claim 2, wherein determining the one or more new operation parameter values for the HVAC system based on at least one of the predicted future net load or the information regarding the current energy price and the future energy price includes:

determining the one or more new operation parameter values for the HVAC system to decrease the power consumption of the HVAC system when the predicted future net load is below the threshold load value, or when the future energy price is lower than the current energy price.

7. The method of claim 6, wherein decreasing the power consumption of the HVAC system includes at least one of:

setting the HVAC to a low power mode;

increasing a temperature set point of the HVAC system;

decreasing a speed of a fan of the HVAC system;

or

turning off a compressor of the HVAC system and increasing the speed of the fan of the HVAC system.

8. The method of claim 1, wherein determining the one or more new operation parameter values for the HVAC system includes one of:

when the temperature is below the lower threshold temperature, determining the one or more new operation parameter values for the HVAC system to turn off the HVAC system;

when the temperature is above the upper threshold temperature, determining the one or more new operation parameter values for the HVAC system to increase a power consumption of the HVAC system; and

when the temperature is between the lower threshold temperature and the upper threshold temperature, determining the one or more new operation parameter values for the HVAC system based on the net load of the site.

9. The method of claim 8, wherein increasing the power consumption of the HVAC system includes at least one of:

setting the HVAC system to a high power mode;

setting the HVAC system to a low power mode;

decreasing a temperature set point of the HVAC system;

or

increasing a speed of a fan of the HVAC system.

10. The method of claim 8, wherein determining the one or more new operation parameter values for the HVAC system based on the net load of the site includes:

when the net load is below the threshold load value, selecting the one or more new operation parameter values for the HVAC system to decrease the temperature;

or

when the net load is at or above the threshold load value, determining the one or more new operation parameter values for the HVAC system based on at least one of a predicted future net load or information regarding a current energy price and a future energy price.

11. The method of claim 10, wherein determining the one or more new operation parameter values for the HVAC system based on at least one of the predicted future net load or the information regarding the current energy price and the future energy price includes:

determining the one or more new operation parameter values for the HVAC system to decrease the power consumption of the HVAC system when the predicted future net load is below the threshold load value, or when the future energy price is lower than the current energy price.

12. The method of claim 11, wherein decreasing the power consumption of the HVAC system includes at least one of:

setting the HVAC to a low power mode;

increasing a temperature set point of the HVAC system;

decreasing a speed of a fan of the HVAC system;

or

turning off a compressor of the HVAC system and increasing the speed of the fan of the HVAC system.

13. The method of claim 1, wherein the one or more new operation parameter values include at least one of:

a temperature set point;

a fan speed;

a temperature cycle time;

or

a high power mode or a low power mode.

14. The method of claim 1, wherein determining the one or more new operation parameter values for the HVAC system is further based on an upper limit of energy cost of the site in a billing cycle.

15. The method of claim 1, wherein the one or more new operation parameter values for the HVAC system include operation parameters for an air conditioner of the HVAC system or operation parameters for a heater of the HVAC system.

16. The method of claim 1, wherein obtaining the net load at the site includes at least one of:

obtaining the net load from a meter;

or

calculating the net load based on a measured gross electric load and a measured actual output of the EG system at the site.

17. A control system for controlling a heating, ventilation and air conditioning (HVAC) system at a site having an energy generation (EG) system, the control system comprising:

a processor;

a memory communicatively coupled to the processor, the memory including instructions executable by the processor; and

at least one meter communicatively coupled to the processor,

wherein the processor is configured to;

obtain, using the at least one meter, a gross electric load and an actual output of the EG system of the site during a time period;

determine a net load at the site based on the gross electric load and the actual output of the EG system during the time period, the net load indicating a difference between the gross electric load at the site and the actual output of the EG system at the site, wherein the EG system includes a photovoltaic system;

obtain a temperature of the site during the time period;

compare the net load to a threshold load value;

compare the temperature to at least one of a lower threshold temperature or an upper threshold temperature; and

control the HVAC system based, at least in part, on the comparison of the net load to the threshold load value and the comparison of the temperature to the lower threshold temperature or the upper threshold temperature.

18. The control system of claim 17, wherein the processor is configured to control the HVAC system by:

when the net load is below the threshold load value, controlling the HVAC system to increase a power consumption of the HVAC system;

or

when the net load is at or above the threshold load value, controlling the HVAC system based on at least one of a predicted future net load or information regarding a current energy price and a future energy price.

19. The control system of claim 17, wherein the processor is configured to control the HVAC system by one of:

when the temperature is below the lower threshold temperature, controlling the HVAC system to turn off the HVAC system;

when the temperature is above the upper threshold temperature, controlling the HVAC system to increase a power consumption of the HVAC system; and

when the temperature is between the lower threshold temperature and the upper threshold temperature, controlling the HVAC system based on the net load of the site.

20. An article comprising a non-transitory computer-readable storage medium including machine-readable instructions stored thereon, the instructions, when executed by one or more processors, causing the one or more processors to:

obtain one or more operation parameter values for a heating, ventilation and air conditioning (HVAC) system at a site having an energy generation (EG) system;

obtain a net load at the site during a time period;

obtain a temperature of the site during the time period, the net load indicating a difference between a gross electric load at the site and an output of the EG system at the site, wherein the EG system includes a photovoltaic system;

compare the net load to a threshold load value;

compare the temperature to at least one of a lower threshold temperature or an upper threshold temperature of the one or more operation parameter values;

determine one or more new operation parameter values for the HVAC system based, at least in part, on the comparison of the net load to the threshold load value and the comparison of the temperature to the lower threshold temperature or the upper threshold temperature; and

control the HVAC system based on the determined one or more new operation parameter values.